The present invention relates to a keyboard arrangement for a typewriter or a data input device for computers or the like having a keyboard subdivided into keyfields each comprising a number of keys.
That the usual keyboard arrangement for a typewriter is not an ideal solution with respect to the arrangement of the keys, (five or six straight rows of keys), nor with respect to the allocation of the individual characters to the keys is proven by the fact a large number of patents were granted during the past fifty years for new keyboard arrangements which are concerned mainly with the allocation of the characters to the keys since with mechanical typewriters and electrical typewriters with mechanical control there were close limits for the arrangement of the keys other than in straight rows. The use of a common axis for all key levels prevented an arrangement of all keys to be operated by a particular finger within a column perpendicular to the row of keys.
The worldwide spread of this arrangement and the worldwide training of specialists for touch typing lead to the maintenance of this keyboard arrangement up to now, even with a partial extension of the keyboard with special keys, although nowadays especially data input devices are provided with fully electric keyboards giving complete freedom with respect to the key arrangement and key allocation.
Investigations of experts have shown that the complaints of operators spending most of their working time with the operation of a keyboard of the type of the usual typewriter keyboard with respect to troubles in hands, arms, shoulders and joints are based on the keyboard being extremely adverse from the ergonomical point of view.
Therefore attempts have been made with respect to a less adverse design of key arrangements. For instance, in U.S. Pat. No. 3,990,565 it was proposed to operate a usual typewriter keyboard via two sets of electrical push-buttons located in separate, widely adjustable housings with the aid of solenoids. Besides the large demand of space and weight this solution has the drawback that the distance between the operator and the typing system is so enlarged that optical aids are needed to read the typed text. Further the wide field of possible positions of the housings would lead to a long personal test phase of the operator.
From the German Pat. DE-OS No. 2 218 065 there is known a keyboard arrangement wherein the usual typewriter keyboard is subdivided into two substantially rectangular fields the narrow sides of which enclose an angle of about 60.degree. open towards the operator. This arrangement of two keyfields in the same plans may help to diminish some of the above mentioned troubles especially those caused by the flexion of the hand with respect to the forearm needed for the usual one-piece keyboard.